I had been preparing my potted roses to go into the ground in the interests of water efficiency. The first was Gloire de Hollande, a favorite of mine and fortunately fine. Then as I de-potted I began to encounter these strange root masses. My brain did not immediately leap into action. It was not until I started to untangle the roots that I realized that the strange masses I was seeing were actually crown gall. It was on several plants.

I discarded the plants, discarded the soil and will scrub out the pots with disinfectant.

I just think it is very odd to find long-established plants with crown gall, growing in pots and separated from each other. I do wonder if my habit of adding mulch and compost to the top of the pots allowed the introduction of the bacteria. Could also have been transferred by me when pruning, though that still leaves the problem of where it came in the first place. BTW, I have never found it on any plant growing in the ground that I have shovel pruned, so it is not running rampant through my garden. (For which I am profoundly grateful.) In my rose reduction campaign I have now removed 36 roses, 7 of which were in pots, and have 6 still to go. You can see that I have looked at a lot of rose roots over the past few weeks. Except for the ones in pots, none of them had this problem.

Any thoughts?

Rosefolly

In general I avoid adding unsterilized material in pots for two reasons. One, the benefit of any 'organic' ammendment in pots is questionable due to the environment being less suitable for the biological processes that are required to make these ammendments useful, and second an infection or pest attack in a pot enviroment can be much more serious for the plant than in the ground. I've seen potted plants decimated in no time by melolontha (cockchafer) larvae, something which would not happen so easily in the ground in a garden environment. I use sterilized susbtrata and so called 'chemical' fertilization for pot plants. I try to treat potted plants more similarly to being hydroponically grown than grown in the ground. Of course the potential for aerial infections is always there but why push your luck?
Nik

Rosefolly

UC Davis published an online article (UC IPM site) on crown gall. The article claimed that soil heated to 160 degrees for 30 minutes is considered clear of gall pathogens. It also stated that a product called Gallex could be used on symptomatic plants. It would not be a choice for organic gardeners...except perhaps ones that are juduciously cheating as a last resort to rescue rare and prized plants in isolation.

Kim's response is encouraging. I remember the days when I had a horticultural breakdown because a prized rose developed mosaic patterns on its leaves. Now, even though I'm not exactly thrilled at the sight, I merely shrug and say, "How decorative."

Carol

It was a lesson learned. Crown gall was something I had not expected to encounter. I really prefer growing roses in the ground, unless someone is in a situation that makes growing them in pots to be necessary. Several gardeners on these forums are in such a situation. Certainly it is better than not having a garden at all.

Rosefolly

And since I have been shovel pruning lots of roses from my garden (about 40 now), I am pretty sure that at least it is not common in the garden here. When you dig them up, you do see a good portion of the root mass. Certainly you see the part near the crown, which seems to be the most common (thought not only) location.

Rosefolly

It doesn't take much wind to lift that up and transport it and drop it.

To think that the gnarly ugliness that are galls come from some thing so small...well, they do. Sadly.